How to use the calculator
This page holds the same Illinois maintenance calculator that appears on the firm's spousal maintenance page. It applies the guideline formula in 750 ILCS 5/504(b-1) to figures you enter. Have each spouse's income records nearby, such as recent pay stubs, tax returns and a Financial Affidavit if one has been prepared.
- Choose the formula. Most people use the standard net-income formula. The second option is only for modifying certain maintenance orders entered before January 1, 2019 that keep their earlier tax treatment, and the tool asks you to confirm that before it uses it.
- Pick annual or monthly amounts. Use the same unit for every income and child support entry.
- Enter gross income for both spouses. The tool uses gross income to check the $500,000 combined-income limit.
- Enter each spouse's net income. Net income has the meaning given in 750 ILCS 5/505, and maintenance in your pending case is left out (750 ILCS 5/504(b-3.5)). The amount of a paycheck deposit is not always the same number.
- Check the prior-obligation box if it applies. Check it if the paying spouse already owes child support or maintenance from an earlier relationship.
- Add child support for the 50% check. Enter any child support the paying spouse would pay the other spouse, if you want the tool to compare the total with the paying spouse's net income.
- Add the length of the marriage for a duration estimate. Enter the marriage date and the date the divorce action was commenced, or a known length in years. You can also enter months of court-ordered temporary maintenance to see a possible credit.
The tool's own notice explains that it processes your figures on this page and that its code does not send, save or add them to a web address. Do not enter names, account numbers or case numbers.
Reading your result
After you select Calculate illustration, the result box shows one of these outcomes:
- Maintenance formula illustration. A monthly and yearly figure, a note on whether the 40% limit lowered it and, if you asked for it, an estimated duration in months.
- An individualized maintenance analysis is needed. The tool shows this instead of a number when combined gross income is $500,000 or more or the prior-obligation box is checked, because the guideline formula does not apply in those cases.
- A 50% review flag. If the estimate plus the child support you entered is more than half of the paying spouse's net income, the tool says so. That is a point the court may consider, not an automatic cap.
- No end date for long marriages. For a marriage of 20 years or more, the tool explains the court's options instead of calculating a fixed term.
A zero result does not mean a spouse has no claim, and a positive result does not mean a court will award that amount. Both depend on the court's findings under 750 ILCS 5/504.
How Illinois guideline maintenance is calculated
Under 750 ILCS 5/504(b-1)(1)(A), guideline maintenance is figured in two steps:
- Take 33 1/3% of the paying spouse's net annual income and subtract 25% of the receiving spouse's net annual income.
- Check the 40% limit. The maintenance amount, added to the receiving spouse's net income, may not give the receiving spouse more than 40% of the couple's combined net income. If it would, the amount is reduced to fit within the limit.
Example (invented figures). Say the paying spouse's net income is $84,000 a year and the receiving spouse's is $21,000. One third of $84,000 is $28,000, and 25% of $21,000 is $5,250, so the first step gives $22,750. Combined net income is $105,000, and 40% of that is $42,000. The receiving spouse already has $21,000, so no more than $21,000 can be added. The guideline estimate is $21,000 a year, or $1,750 a month, because the 40% limit lowers it.
The guide to Illinois alimony laws walks through more examples, including one where the 40% limit does not change the result.
When the guidelines apply
The formula answers the second question, not the first. Under 750 ILCS 5/504(a) and (b-1), the court first decides whether a maintenance award is appropriate at all, after considering all relevant factors, such as each spouse's income and property, needs, present and future earning capacity, the standard of living during the marriage, the length of the marriage, age and health, tax consequences and any valid agreement. If the court finds maintenance is not appropriate, it bars maintenance.
If maintenance is appropriate, the guidelines apply when both of these are true (750 ILCS 5/504(b-1)(1)):
- the spouses' combined gross annual income is less than $500,000; and
- the paying spouse has no obligation to pay child support or maintenance, or both, from a prior relationship.
Even then, the court can find that applying the guidelines would be inappropriate. When the guidelines do not apply, or the court sets them aside, the court decides a non-guideline award after considering the Section 504(a) factors (504(b-1)(2)). Either way, the court must explain its reasoning, and if it departs from the guidelines it must state the amount, if determinable, or the duration the guidelines would have required and its reasons for the variance (504(b-2)).
The 50% check. If guideline maintenance plus child support would be more than 50% of the paying spouse's net income, the court may set non-guideline maintenance, non-guideline child support under 750 ILCS 5/505(a)(3.4), or both (504(b-1)). Our guide to 750 ILCS 5/505, the Illinois child support statute, explains how child support is figured, and the firm's child support page has a separate child support calculator.
Temporary maintenance. The guideline formula in 504(b-1)(1) covers maintenance payable after the marriage is dissolved. Support while the case is pending is a separate request for temporary maintenance under 750 ILCS 5/501. The court decides it on a summary basis from financial affidavits, tax returns, pay stubs, bank statements and other records, although an evidentiary hearing may be held on a showing of good cause. See our guide to the motion for temporary relief.
For combined incomes at or above that level, see high asset divorce.
How long maintenance lasts
Under 750 ILCS 5/504(b-1)(1)(B), guideline duration equals the length of the marriage when the divorce action was commenced, multiplied by a factor:
| Length of the marriage when the action was commenced | Duration factor |
|---|---|
| Less than 5 years | .20 |
| 5 years to less than 6 | .24 |
| 6 years to less than 7 | .28 |
| 7 years to less than 8 | .32 |
| 8 years to less than 9 | .36 |
| 9 years to less than 10 | .40 |
| 10 years to less than 11 | .44 |
| 11 years to less than 12 | .48 |
| 12 years to less than 13 | .52 |
| 13 years to less than 14 | .56 |
| 14 years to less than 15 | .60 |
| 15 years to less than 16 | .64 |
| 16 years to less than 17 | .68 |
| 17 years to less than 18 | .72 |
| 18 years to less than 19 | .76 |
| 19 years to less than 20 | .80 |
| 20 years or more | A period equal to the length of the marriage, or an indefinite term, in the court's discretion |
Example (invented figures). A marriage that had lasted 10 years and 3 months when the action was commenced uses the .44 factor: 10.25 × .44 = 4.51 years, or about 54 months.
In the court's discretion, temporary maintenance paid under a Section 501 court order may be credited against the guideline duration (504(b-1)(1.5)). The court must also state whether maintenance is fixed-term, indefinite, reviewable or reserved (504(b-2)(3)). Fixed-term maintenance is barred after the end date the court sets; indefinite maintenance continues until it is modified or terminated under Section 510; reviewable maintenance runs for a specific term and is then reviewed (504(b-4.5)).
What the calculator cannot decide
- Whether maintenance is appropriate. Only the court decides that, after weighing the Section 504(a) factors.
- Non-guideline cases, including combined gross income of $500,000 or more, a prior support obligation, or a finding that the guidelines are inappropriate.
- Disputes about income. Self-employment income, bonuses, irregular earnings or a claim that a spouse could earn more are decided on the evidence. Each spouse's realistic present and future earning capacity is one of the 504(a) factors.
- Agreements. Spouses can agree on maintenance in a marital settlement agreement. Under 750 ILCS 5/502(b), terms other than those for the support and parental responsibilities of children bind the court unless it finds the agreement unconscionable. See our guide to the marital settlement agreement.
- Taxes. Tax consequences are a statutory factor, but this page does not give tax advice. Ask a tax professional.
- Security and enforcement, such as life insurance to secure maintenance (504(f)) or collecting unpaid maintenance.
Orders entered before 2019
The calculator's second formula is for one narrow situation. When a maintenance order entered before January 1, 2019 is modified, the payments keep their earlier federal tax treatment unless both parties expressly agree otherwise and the agreement is included in the modification order (750 ILCS 5/504(b-4)). For those modifications, if the payments remain taxable to the receiving spouse and deductible by the paying spouse, the guideline amount is 30% of the paying spouse's gross annual income minus 20% of the receiving spouse's gross annual income, unless both parties expressly provide otherwise in the modification order. That amount, added to the receiving spouse's gross income, may not give the receiving spouse more than 40% of combined gross income (504(b-1)(1)(A-1)). A marriage that began before 2019 does not qualify on that basis alone.
For the rest of the law on spousal support, including the factors, modification and termination, read the guide to Illinois alimony laws or see what a spouse may be entitled to in an Illinois divorce.
Talk with a family law attorney
An estimate is a starting point for a conversation. Chicago Family Attorneys handles spousal maintenance requests, responses, modifications and enforcement for clients in Chicago and Cook, DuPage, Lake and Will Counties, from its office in Chicago. Learn more about the firm's work as a Chicago spousal maintenance lawyer.
- Full representation: an initial payment of $1,500 to $2,500, then $500 to $650 per month beginning 30 days after the initial payment while representation remains active. See spousal maintenance fees.
- Limited scope help: drafting from $500 and one hearing appearance from $1,200. See limited scope fees.
Fees are confirmed in writing before you engage the firm, and no lawyer can promise a particular result. Consultations are by phone; a free weekend consultation is available by Zoom. Call 312-965-5618 or book a consultation.
This page and its calculator give general information about Illinois law and an estimate based only on the figures you enter. They are not legal advice for your situation and do not create an attorney-client relationship. Laws and court rules can change.